In MES, users are assigned roles which grant access to different MES features and functions.  MES does have a 250 character limit to the role names assigned to each user.  Example: Production User, Production Receipt User, Production Issue Material User roles assigned to a user would take up 68 of the 250 character limit.  

MES does not warn or prevent you from assigning more than 250 characters of roles to any one user.

One indication that this limit has been exceeded is if the user can't log into MES.  When they enter their username and password MES will go back to the login screen with no error message.  

There are hierarchical roles in MES that grant access to multiple functions with one role.  A good example is System Administration.  There is no need to assign Production User or any other role to a user if they have already been assigned to the System Administrator role.  System Administrator gives the user access to all licensed features and functions in MES.